The present invention relates to printed circuit boards capable of mounting thereon a plurality of electronic components with high density.
This kind of printed circuit boards is disclosed in Japanese U.M. Patent Kokai No. 55-181374. As shown in FIG. 2, this printed circuit board includes a pair of component connection lands 2 and 3 across which a pair of ends 10a and 10b of an electronic component 10 are connected, a pair of signal output lands 12 and 13 each communicating with the connection land, and a pair of wiring patterns 1 and 4 each communicating with the connection land.
The ends 10a and 10b of the electronic component 10 are soldered to the connection lands 2 and 3 by applying a solder resist liquid to the printed circuit board except for the connection lands 2 and 3 and the output lands 12 and 13 and solder to the connection lands 2 and 3 and the output lands 12 and 13.
On the above printed circuit board, however, the signal output lands 12 and 13 must be placed continuously next to the component connection lands 2 and 3, thus limiting the number of electronic components 10 mounted.
In addition, as the number of electronic components increases, so does the number of connection lands to which the electronic components are to be connected, thus increasing the density of the connection lands on the printed circuit board. As a result, it has been difficult or impossible to place a signal output land continuously to the component connection land.